Final answer:
Semi-annually refers to an event occurring twice within a calendar year. Using the context of family visits, if you visit your parents every other Sunday, you would do so 26 times a year, aligning with a semi-annual frequency given the 52 weeks in a year.
Step-by-step explanation:
Semi-annually means something occurs twice a year. It is a term often used in finance and other periodic activities to describe events that happen two times within a calendar year. For instance, if interest on a saving account is compounded semi-annually, this means it is compounded twice a year. Similarly, if someone visits their parents for dinner every other Sunday, and there are approximately 52 weeks in a year, they would visit around 26 times per calendar year. The period between these visits is two weeks. This demonstrates that frequency and period can both describe the same pattern of occurrence but from different perspectives.
The concept also applies to other intervals, such as compounding interest semi-annually in a bank account, or how growth rates might double at a semi-annual rate. For example, if a population doubles every 35 years, it will continue to grow at this rate, achieving a quarter of its ultimate potential in 35 years, a half in 70 years, and so on.